CODEWITHSUNDEEP
bashshellsed
john
john

Reputation: 1075

Using sed to replace text within a java properties file

I have a java properties file that looks like the following:

SiteUrlEndpoint=google.com/mySite

I want to use sed -i to inline replace the url but keep the context path that comes out of it. So for example if I wanted to change the properties file above to use amazon.com then the result would look like:

SiteUrlEndpoint=amazon.com/mySite

I am having trouble with sed to only replace the url and keeping the context path when replacing it inline.

My attempt:

sed -i 's:^[ \t]*siteUrlEndpoint[ \t]*=\([ \t]*.*\)[/]*$:siteUrlEndpoint = 'amazon.com':' file

Upvotes: 1

Views: 1765

Answers (4)

Ed Morton
Ed Morton

Reputation: 203995

Keep it simple:

$ sed -E 's/(SiteUrlEndpoint=)[^.]+/\1amazon/' file
SiteUrlEndpoint=amazon.com/mySite

Upvotes: 0

pakistanprogrammerclub
pakistanprogrammerclub

Reputation: 827

Keep a backreference to the part just before the domain - then match and replace the domain - you can add the -i option after verifying the output of the sed command

url=amazon.com
sed -r 's/\b(SiteUrlEndpoint\s*=\s*)[^/]+/\1'$url'/'

Upvotes: 0

David C. Rankin
David C. Rankin

Reputation: 84579

You can do it with two backreferences, e.g.

sed -i.bak 's|^\(SiteUrlEndpoint=\).*/\(.*\)|\1amazon.com/\2|' file

note: the match of text up to / is greedy. If you have multiple parts of the path following the domain, you probably want to preserve all path components. To make it non-greedy, you could use the following instead

sed -i.bak 's|^\(SiteUrlEndpoint=\)[^/]*/\(.*\)|\1amazon.com/\2|' file

(you can add i.bak to create a backup of the original in file.bak)

To accomplish the same thing, you can match SiteUrlEndpoint= at the beginning of the line first, and then use a single backreference for the change, e.g.

sed -i.bak '/^SiteUrlEndpoint=/s|=[^/]*\(/.*\)|=amazon.com\1|' file

For example, given a file sites containing:

$ cat sites
SiteUrlEndpoint=google.com/path/to/mySite
SiteUrlSomeOther=google.com/mySite

You can change google.com to amazon.com with (using non-greedy form of first example):

$ sed -i 's|^\(SiteUrlEndpoint=\)[^/]*/\(.*\)|\1amazon.com/\2|' sites

Confirming:

$ cat sites
SiteUrlEndpoint=amazon.com/path/to/mySite
SiteUrlSomeOther=google.com/mySite

and

$ cat sites.bak
SiteUrlEndpoint=google.com/path/to/mySite
SiteUrlSomeOther=google.com/mySite

Explanation (first form)

  1. sed -i.bak 's|^\(SiteUrlEndpoint=\) - locate & save SiteUrlEndpoint=
  2. [^/]*/ - match any folowing characters up to first / (non-greedy - adjust as needed)
  3. \(.*\) - match and save anything following /
  4. |\1amazon.com/\2|' - full replacement (explanation below)
  5. \1 - first back-reference containing SiteUrlEndpoint=
  6. amazon.com - self-explanatory
  7. /\2 - the '/' second back-reference of everything that followed.

Look over all the solutions and let me know if you have questions.

Upvotes: 3

chw21
chw21

Reputation: 8140

Regular expressions are hard, especially with complex regular expressions and/or large input files where unexpected changes are to be avoided.

Therefore I strongly recommend using sed -i.bak to keep a backup of the original file to then run a diff on both of them to see what changed.

Assuming that

  1. You only want to change things after the tag siteUrlEndpoint (case insensitive)
  2. You want to change the URL to amazon.com while leaving the path intact

I came up with this solution:

sed -i.bak 's;^\([ \t]*siteurlendpoint[ \t]*=[ \t]*\)[^/]*\(.*\);\1amazon.com\2;Ig' infile

I used a semicolon instead of your colon, that's just my preference when I don't want to use / ;)

Then I wrapped both the leading white spaces and siteurlendpoint as well as everything from the first / onwards into brackets \( \) so that I can take them again in the replacement with \1 and \2. That way I keep the indentation and the capitalisation of SiteUrlEndpoint intact.

For the search options I added an I to the g to make the search case insensitive. I am not sure how standard this option is, you might have to see whether your sed understands it.

The actual part that I want to replace I have just any character not including the next /: [^/]*

As for your line:

  1. Your search term only searches for siteUrlEndpoint with lower case s. Since in your examples you wrote it with capital S, it wouldn't have triggered.
  2. The final [/]*$ doesn't make any sense at all. "This line can end in zero or more of any of these caracters: /."
  3. You precede this [/]*$ with .* which means: zero or more of any character at all.
  4. The single quotes around 'amazon.com' might interfere with the single quotes around the whole search/replace term. It seems to work, but it is sloppy, and will fail if there are ever any spaces in there. It doesn't seem to serve any purpose anyway (except if you want to replace amazon.com with some environment variable like $NEWSITE) so I don't know why you're doing that.

Upvotes: 0

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